Stethoscope



SOLOMON H. RUBIN, or ROXBURY, MASSACHUSETTS.

STETHOSCOPE.

Specification of Letters Patent.

Patented June 29,1920.

Application filed June 30, 1919. Serial No. 307,699.

To all whom t may concern: e

Be it lrnown that I, SOLOMON H. RUBIN, a citizen of the United States,and resident of Roxbury, county of Suffolk, State of Massachusetts, haveinvented an Improvement in Stethoscopes, of which the followingdescription, in connection with accompanying drawing, is aspecification, like characters on the drawing representing like parts.-

This invention relates to improvements in stethoscopes and the principalobject thereof is to provide an instrument which will more distinctlydetect and transmit sound.

Another object of the invention is to provide a stethoscope which willreduce the effeet of interfering sound waves and enable the operatormore distinctly to detect the condition for which he is exploring.

Another object of the invention is to provide a stethoscope adapted tobe employed under varying conditions requiring different sound receivingapparatus.

Another object of the invention is to pro vide a stethoscope with anoneonducting contacting face to be applied to the body whereby the`chill which occurs from the use of a metallic instrument in coldweather ma be avoided. Y f

nother object of the invention is to provide a stethoscope of thecharacter above `described with a diaphragm which will amplify the soundwaves transmitted to it from the body. y

`Other objects and features of the invention will more fully appear fromthe following description and the accompanying drawings and will bepointed out in the annexed claims.

- In the drawings: Y y y,

Figure l is a plan view of the .back of the stethoscope embodying myinvention,

Fig. 2 is a vertical longitudinal sectional view of one of the preferredforms of stethoscope embodying my invention showing, adjacent the headof said stethoscope, a diaphragm and a cap adapted to bev detachablysecured to said head,

Figu' is a front elevation of a desirable form of cap,

Fig. 4 is a view partly in vertical section of a modified form of thestethoscope in which the head includes a bell shaped member which may bedetachedand used alone,

Fig. 5 is a front elevation of the head showing the apertures havingcountersunk yand 4 of the accompanying drawing comprises-a head l havingan elbow extension 2 provided with a nipple 3 to which a tube 4i of theusual transmitter is connected. AThe transmitter may be and is of ausual type includinga Y member, one branch 5 of which is connected tothe tube l while the other branches 6 and 7 are connected by flexibletubes to the usual ear piece (not shown).

The head l desirably is in the form of a cylindrical metallic or woodenplate, the outer portion of which has a concave face 8 providing areceiving chamber 9 adapted to be placed adjacent the body. The head lis also provided with a resonance chamber 10 having a concave face 11reversely arranged to the face of the receiving chamber. The back l2 ofthe head desirably` presents a fiat face 13 for the rear wall of theresonance chamber l0, said back being welded, soldered or otherwisesecured permanently to the head l.

The elbow extension may be and desira-bly is integral with the back l2.The wall lll which separates the receiving chamber from the resonancechamber is provided with minute perforations l5 preferably located inthe periphery of a circleat a considerable distance from the center ofthe head. The walls of said perforations preferably are countersunk toprovide conical recesses 16 having theirA apeXes leading `to theapertures l5 whereby the area of the wall of the receiving member isincreased.

Other series of perforations 17 and 18 may also be employed with orwithout .the

'countersunk portions above specified.

The membersgof each series of perfora- .tionsthrough thewall between thereceiv- 4ing'andresonance chamber are at equal .radial'distances fromthe center of. the ychamber so that the pulsations of circular soundwaves expanding from an axial linethrough the center of the soundreceivingk chamber will pass through all of the perforations of a seriesat the same time. The

,portions of the soundwave thus trans'- the resonance chamber againstthe concaved forward surface thereof and thence through the passageleading to the tfansmitter. By reason of this construction what may betermed as selective waves are transmitted through the perforations tothe resonance chamber and thence to the transmitter and many interferingsound waves are suppressed so that the sound which enters the receiveralthough greatly decreased in volume is more distinct and enables thephysician to determine more accurately the conditions which he isexploring.

In order further to control the volume of sound thus transmitted anadjustable valve is placed in tl e passageway leading from the resonancechamber to the 'transmitte Preferably the valve is in the form of aconical or needle valve 19 which extends through the elbow axiallytoward the passage leading from the resrmince chamber and cooperateswith the circular valve scat 20 at the end of said passage. The valve 19is provided with a screw threadeil stem Q1 which engages complementaryscrew threads in the extension The extension Q2 desirably is providedwith a cap 23 screwed upon the end of the extension 2Q, and a washer 24Cof fibrous material clamped between the cap and the end of the extensionadapted to engage a shoulder at the end of the screw threaded portion ofthe stem to prevent the valve from being withdrawn beyond a certaindistance. The valve stem may be provided with a milled head QG forconvenience in operatirin.

In order to ada-pt the instrument for a greater variety of uses,particularly when the transmission of an amplified volume ot sound isdesirable, .means are provided for securing a diaphragm across theotherwise open face of the sound receiving chamber.

In the construction illustrated herein a diaphragm 27 of hard rubber,metal or other suitable material is provided which may be secured uponthe head of the transmitter by an annular' retaining ring 28, asillustrated in Fig. t, having a screw threaded flange 29 adapted toengage peripheral screw threads 30 upon the head l.

A cap 31 of rubber or fibrous material may be provided to cover thereceivingface of the stethoscope to protect the body of the patient fromchill of the metal portions against him in cold weather. The cap preferably is provided with apertures which permit the entrance of thesound waves into the sound receiving chamber and when a diaphragm isused act as chambers which amplify the. transmission of the sound waves.

It will be understood that the instrument however may be used withoutthe diaphragm or the cap or with the diaphragm retained upon it by thering 28 as illustrated in Fig. l or without the diaphragm and with thecap 31 or with the diaphragm and the cap as above described, accordingto the requirements of the examination which is to be made.

In the use of the instrument the countersunlr portions 1G leading to theapertures 15 serve to enlarge the capacity of the sound receivingchamber and also serve te prevent the plugging up of the aperti'ires bythe 'liesh of the patient when the instrument is pressed .firmly uponthe flesh.

In Fig. -il a modified form of stethof-scope is illustrated in which awall b, veen the receiving and resonance chambers is o t wood which isadapted to increase the resent-.rice of the device. The rear wall of theresonance chamber is recessed and a bell shaped member 33 removablyattached to i screw threaded connection. The che-.i of the bell-shapedmember has an elbow ej:- tension 3G provided with a nipple 37 leading tothe transmitter. conical needle valve similar to the valve 19 desirablyis provided for controlling the volume of sound allowed to pass to thetransmitter, the needle valve being` actuated by a milled disk 3S uponthe stem 39 of said valve.

In this form of instrument the head portion l containing the sound Ltransmission and resonance chambers may be removed and the bell employedas a stethoscope, this being particularly useful when desired to explorea small area` and to receive a greater volume of sound or in theexamination of infants.

lllhen the head l Vis used in connection with the bell 55? asillustrated ,in llig. Althe resonance chamber i() is suppleinented bythe chamber 35 of the bell 33, otherwise the operation of thestethoscope illustrated in. Fig. 1 is the same as that illustrated inthe remaining figures. The diaphragm 27 or the cap 3l may be applied tothe form illustrated in Fig. 4l; in the same manner as to the formillustrated in Figs. 1, 2 and as above described.

It will be understood that the embodiment of the invention disclosedherein is illustrative and not restrictive and that various changes maybe made within the spirit and scope of the following claims, for examplethe elbow shaped extension with its valves may be omitted and thetransmitter caused to communicate directly with the bell or theresonance chamber, that modifications in the form of the receivingresonance chamber may be made, that the cap may be formed with orwithout perforations and that various other changes may be made withoutdeparting from my invention.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent, is:

1. A stethoscope comprising a head and a transmitter, said head having a'sound rey ceiving chamber, and a resonance chamber located behind saidsound receiving chamber, the wall between said chambers having minuteperforations located at a distance from the center of said chamber and apassageway leading from said resonance chamber to said transmitter.

2. A stethoscope comprising a head and a transmitter, said head having asound receiving chamber and a resonance chamber, the wall between saidchambers being provided with reversely concave faces, a series of minuteperforations located at equal distances from the center of said chambersandl a passageway leading from said resonance chamber to saidtransmitter.

3. A stethoscope comprising a head and a transmitter, said head having asound receiving chamber and a resonance chamber located behind saidsound receiving chamber, the walls between said chambers being providedwith minute perforations having counter-sinks leading from the soundreceiving chamber to said perforations and a passageway leading fromsaid resonance chamber to said transmitter.

4. A stethoscope comprising a head having -an L-shaped extension, atransmitter connected thereto, said head having a sound receivingchamber provided with a concave face, a resonance chamber behind saidsound receiving chamber, minute apertures leading through the walls ofsaid chambers located at distances from the center thereof, a passagewayleading from said resonance chamber to said transmitter through theeX-v.

tension of said head, and a conical valve adjustably mounted in saidelbow adjustable to restrict the volume of sound transmitted throughsaid passageway. o n 5. stethoscope comprising a head, and atransmitter, said head having a sound receiving chamber and a resonancechamber located behindv said receiving chamber, apertures through thewall between said head and said resonance chamber, a bell detachablysecured to said head communicating with and forming a part of saidresonance chamber and a passageway leading from said bell to saidtransmitter.

6. A stethoscope comprising a head, and a transmitter, said head havinga sound receiving chamber and a resonance chamber located behind saidreceiving chamber, apertures through the wall between said head and saidresonance chamber, a bell detachably secured to said head communicatingwith and forming a part of said resonance chamber, an elbow extension onsaid head having a passageway leading to said transmitter and a conicalvalve located in said elbow extension adapted to restrict the volume ofsound passing through said passageway.

A stethoscope comprising a head and soLoMoN RUBIN.

